Conditioning personal care compositions comprising various combinations of detersive surfactant and hair conditioning agents are known. These personal care compositions typically comprise an anionic detersive surfactant in combination with a conditioning agent such as silicone, hydrocarbon oil, fatty esters, or combinations thereof. These personal care compositions have become more popular among consumers as a means of conveniently obtaining hair conditioning and hair cleansing performance all from a single hair care product.
Many conditioning personal care compositions, however, do not provide sufficient deposition of conditioning agents onto hair or skin during the application process; if deposition is possible, it is only possible in formulations with relatively low levels of anionic surfactant. Without such deposition, large proportions of conditioning agent are rinsed away during the application process and therefore provide little or no conditioning benefit. Without sufficient deposition of the conditioning agent on the hair or skin, relatively high levels of conditioning agents may be needed in the personal care composition to provide adequate hair or skin conditioning performance. Such high levels of a conditioning agent, however, can increase raw material costs, reduce lathering, and present product stability concerns. Additionally, limitations on total anionic surfactant in order to form coacervate can limit the lather potential for a formula, or result in the need for higher levels of more expensive amphoteric surfactants to achieve good lather.
One known method for improving deposition of a hair conditioning agent onto hair involves the use of certain cationic deposition polymers. These polymers may be synthetic, but are most commonly natural cellulosic or guar polymers that have been modified with cationic substituents.
The formation of coacervate upon dilution of the personal care composition with water is important to improving deposition of various conditioning actives, especially those that have small droplet sizes (i.e., ≦2 microns). Dilution generally occurs during the usage of the personal care composition, for example, when a person applies a personal care composition to wet hair, the product is automatically diluted with water. In order to form coacervate, a personal care composition containing typical cationic polymers, such as natural cellulosic or guar polymers that have been modified with cationic substituents, tend to be significantly limited in total anion concentrations in order to achieve adequate levels of coacervate upon dilution. For example, limiting the total level of sulfate in a sulfated anionic surfactant will encourage coacervate formation but will limit the volume of lather that can be achieved with a particular personal care cleansing composition. Thus, for low cost, high lathering, coacervate forming compositions, it is desirable to use a cationic polymer that can form coacervate with higher levels of anionic surfactants.
A need still exists for improved conditioning and lather performance in personal care compositions.
It has now been found that select synthetic cationic polymers provide improved conditioning performance, especially wet hair conditioning, and improved deposition of dispersed hair conditioning agents onto hair or skin. These select polymers are especially effective at improving deposition of dispersed hair conditioning agents onto hair and skin, through coacervate formation upon dilution. In one embodiment, coacervate formation is optimized when formulated in combination with certain levels of anionic detersive surfactant in a personal care composition.